


How Do You Feel?

by doctorcanon



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Advisor Seteth, Anal Fingering, Anal Sex, Blow Jobs, Enthusiastic Consent, Fluff and Smut, Happy Sex, Lowkey Everyone Lives/Nobody Dies, M/M, Plot What Plot/Porn Without Plot, Snarky Byleth, Unusual relationship
Language: English
Status: Completed
Published: 2021-01-29
Updated: 2021-01-29
Packaged: 2021-03-15 15:48:37
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,184
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29066838
Author URL: https://archiveofourown.org/users/doctorcanon/pseuds/doctorcanon
Summary: "As the new Archbishop and Headmaster, Byleth takes care of logistics. Everyone’s well being is his responsibility. It’s Seteth’s job to take care of Byleth. And right now everyone’s famously stoic professor is clearly in a bad mood."Byleth has been pretty grouchy...well...grouchier than usual lately and has been holing himself up in the Training Hall to blow off some steam. But of course, Claude tips off Seteth; the only one who really knows how to deal with him when he's like this. However, the two men have their own issues to sort out.
Relationships: My Unit | Byleth/Seteth
Comments: 2
Kudos: 32





	How Do You Feel?

**Author's Note:**

> Honestly, this is just something fluffy and sexy with no real plot. M!Byleth doesn't get a lot of love so here's him getting dicked down by one of my favorite characters.

As the new Archbishop and Headmaster, Byleth takes care of logistics. Everyone’s well being is his responsibility. It’s Seteth’s job to take care of Byleth. And right now everyone’s famously stoic professor is clearly in a bad mood. Byleth is naturally curt but he never outright ignores anyone. So when he walks right past Dimitri without acknowledging him, Seteth can’t help but follow him as he carries out his daily duties. He tries to be discrete but a few of their former students notice him. However, they just nod knowingly and let him carry on. Even Flayn doesn’t ask questions. He doesn’t bother saving face. He considers confronting Byleth at lunch. However, he doesn’t show up. He doesn’t show for dinner either. Byleth’s Crest of Flames gives him a nearly endless appetite that only got worse after he obtained the Sword of the Creator. The last time Byleth skipped meals, Jeralt died. No, it’s not just a bad mood. Something is _wrong_. 

It’s night now and Byleth isn’t in his room. No one seems to know where he is either. However Claude makes it his business to know where everyone is at all times and he smirks when Seteth tells him what’s going on. Why must he always smile like that? Can’t he see this is serious?

“Look, I know you and Teach are super close and everything, so you’d know more than me.” Claude says with a shrug. 

“What are you implying?” Seteth asks, not amused in the slightest.

“Nothing.” Claude says in a way that implies that it’s definitely _something_ . “It’s just that you two spend so much time together. You’re his advisor. Maybe you can _advise_ him to take a break or several.” 

“I would appreciate it if you didn’t speculate on the nature of mine and Byleth’s relationship.” Claude burst out laughing then.

“Speculate? Yeah. Okay, Seteth.” The Almyran King claps him on the shoulder. “Teach is in the Training Hall. Be careful though. He’s in a rare mood.” With that, Claude walks off joining Edelgard and Dimitri who wait patiently at the end of the hall. Now alone, Seteth is the one left speculating. 

Byleth isn’t a normal person. It’s odd enough that his mood is bad enough to affect the way he acts. Selfishly, Seteth feels a bit put out. When Byleth is at a loss with his emotions, he comes to Seteth. They trust each other. Byleth is more than kin. There’s nothing they can’t talk about. So why can’t they talk about this? Is he avoiding him? Is he the problem? These questions plague him all the way to Training Hall where Byleth is brushing up on his hand to hand combat. 

Before he came to the monastery, Byleth relied solely on his unusual strength and a mercenary’s rough and tumble training. But at the monastery, Byleth has been able to refine his skills in armed and unarmed combat. He’s still lithe and wiry but that doesn’t stop his biceps from filling out his sleeves and his back muscles from straining against his tight training shirt. He’s in his element here. Byleth lives to fight. He enjoys conflict even if it’s with himself. He always claims that it’s a sign of progress. Of course a mercenary would think that way. He’s gorgeous with a sword but the way he moves in hand to hand combat is almost musical. He could watch that muscular, flexible body bend for hours. 

“Goddess, Seteth, stop staring.” Well it seems he enjoyed the show for a little too long and blew his cover. Or perhaps Byleth knew he was here all along. It’s impossible to tell. Byleth continues kicking and bunching the rotating wooden dummy. “Did Claude tell you I was here?” 

“After you didn’t show up to dinner, yes.” Seteth replies. 

“I told him to stop meddling.” Byleth mutters, punching the dummy particularly hard. 

“You ought to tell the wind to stop blowing while you’re at it.” Seteth replies. Byleth snorts in laughter but when he looks back at Seteth, he forces the smile from his face and keeps battering the dummy. “It’s late, how about you call it a night?” 

“No. I’m fine.” Byleth replies. If Seteth didn’t know any better, he’d say that he sounds a little bratty. 

“Nonsense.” Seteth says. He steps down into the ring and marches it up to the dummy holding it still. “You’re still in peak form, surely but we can’t risk losing you to exhaustion. You’d hardly be able to look Jeralt in the eye in the afterlife.” Byleth gives him an almost feral scowl. 

“I’m sure if he knew how long I had to spend with _you_ everyday, he’d understand.” He snipes. Seteth can’t help but take the bait. He hasn’t been able to banter like this with anyone but his wife.

“I wouldn’t have to shadow you, if you were more conscientious.” He admonishes, feeling a wry smirk spread across his face.

“I am plenty _conscientious_.” Byleth says smoothly. “I get things done regardless of what order you say they need to be in.” 

“Contrary to popular opinion, Professor, I don’t need the order at all.” Seteth rounds the dummy and stands toe to toe with Byleth on the other side. “Only that you watch that sharp tongue of yours.” 

“Are you serious?” Byleth’s scowl is a little less than playful now. “My tongue is what keeps the nobles from begging for alms at our doorstep.” 

“Those people have lost their titles, you can’t expect them to accept new rule so easily, Byleth.” Seteth admonishes with a wag of his finger. Something flashes in Byleth’s eyes. Whatever it is makes him sneer and step closer to Seteth. Their faces are nearly close enough to touch noses. 

“I’m not Flayn, Seteth, don’t lecture me.” Byleth hisses. Seteth also steps closer. So close that their noses bump. He’s even able to place his hand over the dummy trapping Byleth in place. 

“You’re not a child, Byleth but if you talk to me like that again, I will spank you.” 

Byleth’s eyes dilate.

“Coat. Off. Now.” He demands. It’s Seteth’s turn to smirk now. 

“A friendly match?” He asks, already taking his cape, overcoat and shirt off. He folds it neatly and places it away from the dirt. He removes his boots, so it’s a fair fight. Under all those clothes, no one sees the brawn he’s built up over the years and that’s just how he likes it. Though not by much, he’s bulkier and hairier than Byleth. When he was younger, he was built more like Dimitri. Back then, it was much harder to be subtle about his abilities. He has to admit, there’s a certain thrill with knowing that people underestimate him. Byleth, however, always takes him seriously. So he’s a little surprised to see the younger man stare dumbly at him as he strips down to his breeches.

“Name your terms.” Byleth recovers slightly shaking his head. 

“First pinned wins.” Seteth says easily. Byleth regards these terms with a dubious glare. “Unless you have something to add.” Byleth responds by getting into a fighting stance. He embodies the element his name represents, he’s the ocean until it’s disturbed. Seteth is a little different. He might fight in the air, but he’s like a rock on the battlefield; unmovable and merciless. Byleth moves first and the battle is on. 

It’s like a clash of titans. The students will be sad they missed this. This is just a sparring match but they aren’t the kind of men that pull their punches. Especially not for each other. Seteth is quite sure he’ll bruise tomorrow but he won’t regret it as long as everything works out. Byleth doesn’t care where Seteth hits him. He feels electric. It’s almost like the first time someone was gentle with him. He’s only been able to express emotions for little more than a year now. He doesn’t know what he’s feeling but he feels it so deeply that he needs to take it out of Seteth’s face. That is until his back hits the floor and Seteth pins him by his arms. The man is right on top of him, framed by the torch light above. He’s glowing with a fine sheen of sweat and Byleth swears the man has a faint dusting of pink in his cheeks from exertion. 

“Do you yield?” Seteth’s voice sounds different. It’s not his usual prickly tone of propriety and punctuality. It’s like dark, rich velvet. Byleth kicks Seteth legs out and when the man loses his grip, he flips them over. Now he’s on top, straddling Seteth’s waist.

“Make me.” Byleth growls. Seteth doesn't usually answer a challenge so Byleth doesn’t expect to be rolled right back over onto his back. Seteth doesn’t just have him pinned by the arms now, but he can’t move his hips so he doesn’t have enough room to kick.

“Gladly.” There’s the voice again. It sends a jolt through Byleth that makes his hips arch up into Seteth’s. He feels hot. It’s different from the heat of training. This sends jolts all through his body and connects him to Seteth. The friction sends tingles from his crotch to the rest of his body. “Give into it.” Seteth whispers. Byleth’s back arches again. This time the friction makes him gasp and Seteth locks their open mouths together. 

The next minute, he and Seteth are kissing so much it’s hard to tell which tongue is his. Byleth has kissed before, but never like this. He can’t name the feeling but it makes him want to wrap his arms around Seteth and grab a handful of his hair. So he does. And Seteth _likes_ it, smiling against his lips as they grind their half mast erections together. 

“Seteth…” He mutters into his open mouth. “I…” Byleth’s mind goes blank when Seteth grinds against his hips. 

“Take your time…” He’s not being playful. He wants him to say it. 

“I…” Byleth feels something. What does he feel? He feels hot. The heat makes him crave. He wants more and only Seteth can give it to him. “I want _you_ .” Seteth takes Byleth’s hand and places it on his chest of his rapidly beating heart. That rhythm belongs to Byleth now. He wants to remember it for as long as he lives. He can’t help but notice that Seteth’s chest muscles are bigger than his hand. “I want you _so badly_.” 

“You have me.” Seteth declares quietly. Byleth sees something in Seteth’s eyes as he says those words. He just told him a secret. They are the only two people in Garreg Mach, nay the entire world that knows about this moment right now. That alone compels Byleth to kiss Seteth more. But then Seteth nips at his neck. A spasm of pleasure travels straight to his cock. He bucks wildly against Seteth as a loud, lusty moan leaves his throat without his permission. Seteth is just surprised as he is. “Would you like me to make you do that again?” Seteth asks, with a roguish charm he’s never seen before. Byleth can’t even speak, he just nods eagerly. Seteth chuckles. “Then I want you bathed and in my room in an hour is that clear?” 

Byleth makes it forty five minutes.

Seteth waits for him in nothing but a dressing gown. Byleth hates his smug smile and strides across the room to kiss it off. Byleth prides himself on his lightning reflexes but he has no idea how Seteth gets him on his back a second time. Seteth's weight buries him in the duvet and pillows. His teeth nip at his tongue and lips. A little thrill overcomes Byleth as he realizes Seteth's calloused hands are big enough to hold _both_ of his hands over his head with one and travel alongside his body with the other. Seteth palms his erection and he's desperate for more. He curses under his breath. He's so hot, and he craves so badly. 

"Tell me what you're feeling." Seteth demands quietly. He presses a little harder on Byleth's erection. 

"Hot…"

"And?" Seteth's hand dips under his waistband. Byleth whines. He's never heard that sound from his dear professor. He's a lot more desperate than Seteth initially thought. 

"Want…" 

"Anything else?" Seteth strokes Byleth's cock gently. 

"I don't know!" Comes Byleth's frustrated answer. "I've never been so hot and I - shit! - can't...can't focus. I can't stop it, I can't help it…!" He's breathless, clawing at Seteth wanting more and not knowing why. Seteth's body vibrates with anticipation. He’s so firm, deceptively muscular and marred by several scars. He's _beautiful_. Seteth squeezes his balls firmly and the confession rushes out of his lungs. "And it only happens when I think of you…!"

Seteth is shocked for a moment. He and Byleth aren't regularly intimate save for that one time after a particularly harrowing battle. Their relationship is unique. They are not romantic people. Their duties have always been more important. Have they truly not thought of how that might change now that the war is over? Byleth will always struggle with his emotions. As old as he is, Seteth perhaps knows how to cope too well. He's glad to help Byleth along. He chuckles blithely, letting go of Byleth's wrists and runs his thumb against his bottom lip. 

"What you're feeling is sexual frustration." Seteth says. Byleth makes a confused squawk in response. "It can be quite vexing. Shall I relieve you?" He just nods rapidly. 

Desire pulls him closer to the edge to some great, unfathomable light at the end of the tunnel. He's teetering on the edge of something great. He's never been in the light before but when Seteth moves his pants down and gives his cock a long, languid lick, he completely surrenders himself to it with a loud moan. He feels like he's floating. The light shines on him making him feel warm and excited. Holy shit, he's never wanted something - _someone_ \- so badly. 

"Don't worry, Byleth, I'll take care of you." Seteth slips his mouth over Byleth's flushed cock. He relishes in the sound of Byleth's moaning. He's surprised to hear how loud he is. Byleth has never been particularly vocal. So he sucks a little faster and Byleth's voice hits a new octave and his back arches off the bed. 

"Seteth!" That pleading exclamation comes with a tug on his hair. His wife used to do the same thing. It only makes him want to press him more and give him more pleasure. Before long, Byleth is a panting, mewling mess, gripping Seteth's hair in one hand and the duvet with another. "Please...please...oh goddess I can't….holy shit…" Byleth can't even get a sentence out. As expected, he's already close. He sucks Byleth all the way down. He takes his time, drinking up every moan and sigh he hears. "Oh fuck...fuck! Seteth...Seteth, I'm...I'm…!" That's all the warning Seteth needs. He lifts his head just as Byleth comes all over his hand. A bit gets on his face but he doesn't mind. Byleth throws an arm over his face, trying to catch his breath. He's never cum that hard before. He's almost lightheaded. Seteth cleans off his hand and Byleth peeks from under his arm to find the man's impressive erection poking out from between Seteth's robe. Byleth sits up as he removes it and let's it fall to the floor. His mouth waters at the sight of Seteth erect and naked.. 

"No, don’t get up. I'm not done with you." Seteth thumbs his bottom lip again and Byleth suddenly feels the need to suck it. Next thing he knows, Seteth's middle fingers are in his mouth and he's sucking on them like they're his cock. He wants to suck the real thing so badly. It's so _long_ and _thick_ and _holy_ _goddess_ , he wants it inside of him. He wants Seteth to unmake him. But Seteth keeps him from sitting up. "You'll have your turn, but _I'm_ taking care of _you_ tonight." 

Seteth gives Byleth a pillow and he tucks it under his hips. People will talk if they're both limping tomorrow. Seteth takes a small jar filled with oil from his bedside table drawer. Byleth can't help but laugh but he doesn't know why. 

"How are you feeling now?" Seteth asks.

"Happy." Byleth replies. He looks at Seteth's glorious erection and bites his lip. "Eager." That's what Seteth hoped to hear. He coats his fingers in the oil and sets himself back on the bed between Byleth's legs. 

"Are you ready?" Seteth asks. Byleth nods, deletes blown wide with anticipation. The oil made Seteth's finger's cold so the first finger is actually a little uncomfortable. However, Seteth's experience pays off. Byleth's nipples are hard and flushed. He reaches out and thumbs them gently. Byleth twitches. He doesn't want to tease the poor professor. Yet. He pinches Byleth's left nipple hard and the younger man cries out with a mix of arousal and surprise. 

"I...I didn't know they could do that…" Byleth mumbles, trying not to drool. 

"Would you like me to do it again?" Seteth croons. Byleth nods rapidly again. He gives the nub a harsh pinch and adds a second finger at the same time. He curls his fingers and Byleth's moans start to sound like prayers. "You're getting hard again." Fumbling, Byleth starts stroking himself into full erection. While he's distracted, Seteth is about to add a third finger until Byleth stops him. "I'm going to need to prepare you thoroughly, my dear." He admonishes gently. Now it's Byleth's turn to smirk.

"I want it to hurt…" the finality in his voice hits Seteth right in his balls. The dragon inside him roars. He rolls on top of Byleth and marks his neck with youthful abandon he hasn't felt in decades. Byleth isn't gentle and Seteth hasn't ever done anything halfway. He's going to do Byleth as rough and as thoroughly as possible. "I want to feel you," the fire in Byleth's eyes turns dark and primal. He licks his lips, never breaking eye contact with Seteth. More predator than man, he wraps his arms around Seteth's neck. "I want you to hurt me." 

For a moment, Seteth loses his infamous self control. Growling, he flips Byleth over and hauls his hips up to his knees. He grinds his cock into the cleft of his ass. He's only able to calm himself down enough to remember a little more oil. Overcome with a need to fulfill Byleth's request, Seteth brings his hand down with a rough 'smack'. Byleth cries out like he's come for a second time. He does it again, hard enough to leave a red hand print. And again, just to watch Byleth's taut, muscular ass jiggle around his cock. 

Byleth whimpers, needily pressing his ass into Seteth's hips. He's never wanted like this before. It's like falling through the air and it makes him wonder what a complete loss of control would feel like. He wants to be at Seteth's mercy.

"Please…" Byleth groans over his shoulder. He's not a virgin. He's not fragile. And he's tired of waiting. "Fuck me, Seteth. Fuck me like I belong to you." He nearly cries in relief when Seteth buries his cock balls deep inside him.

The dragon claims his prize. He hoards those moans and shouts like precious gold. Seteth's lost all control. He grabs Byleth's hips and instantly sets a brutal pace. Byleth basks in the stretch and burn. He doesn't care about walking straight tomorrow. He doesn't care if he's shouting actual words into the pillow. 

“Your hole was made for me.” Seteth growls out. He grabs Byleth’s shoulders, pulling him flush against his chest. Whatever Byleth screamed into the pillow comes bursting out. He can’t help it. He’s never felt this way before. His body sings and he can do anything other than sing with it. Seteth’s puts a hand around his neck to stabilize him but he nearly loses his mind at the thought of the man choking him. 

"Fuck…! Seteth! Please…!" Byleth can't string together a coherent thought. He hardly knows what he's begging for. He just wants more. He cries out from each deep, unyielding thrust. Their kisses are sloppy but fiery. Seteth growls hungrily into his mouth but holds him close like something precious. Mixed with the lust and pleasure is relief. The relief that he finally belongs somewhere. He's wanted and cared for. He trusts Seteth, he wants him. Every part of his body screams to be wanted back. 

"Byleth…" Seteth moans. "Yes…yes, my love...you feel incredible…" _My love_ . He hadn't even realized he said it until it came out of his mouth. He slows his thrusts, resting his head against Byleth's shoulder. Honestly, Seteth thought he'd never say those words again and if he did, perhaps they'd feel strange maybe even _wrong_. But holding Byleth in his arms and kissing up his neck, he's found a piece of him that's been missing for so long. 

"Seteth? What's…?" Byleth doesn't get a chance to finish his sentence. Seteth roughly flips him over. He tries to say more but Seteth kisses him to silence any apprehension. Seteth revels in the way his dear professor melts into the kiss but it's just as sweet when Byleth cries out as he thrusts back into his wet heat. 

"Look at you…" Byleth thought this couldn't get anymore intense but looking into Seteth's eyes leaves him breathless. He leans into Seteth's touch as he caresses his cheek. He licks and sucks the thumb that finds its way into his mouth. For a moment, he's utterly lost in Seteth's gentle smile. He almost doesn't register Seteth throwing his leg over his shoulder. "I'm going to watch you cum." Seteth declares with a forceful thrust. The new angle makes Byleth see stars. Seteth is back to his brutal pace, thrusting relentlessly. He takes the hand from his face and starts stroking his bobbing, neglected cock.

"Setethsetethseteth…" This is the closest Byleth will ever come to worship. All he can do is hold on. He tries to keep looking into Seteth's eyes but the wave doesn’t just break over him, it overtakes his entire body. His back arches, the corners of his vision close in, ropes of cum splatter across his chest and he cries out Seteth's name as pleasure sends tremors through his body. Seteth explodes inside of him with a load moan. Warmth fills his insides and only makes his orgasm that much more satisfying. 

Byleth doesn't wait to bask in the afterglow. He instantly pulls Seteth down for a slow, languid kiss. He's not good with words, so he tries to put everything he's feeling into it. Seteth gets the message holding him tightly, nipping at his lips. Then the exhaustion suddenly kicks in and the both collapse onto the bed breathless with their foreheads touching. 

"That...that was…"

"You don't have to say it." Seteth says gently. 

"Holy shit." Byleth's voice cracks. He laughs a bit deliriously. Tears feel his eyes. "I can't...Seteth...I…"

"Shhhh…" Seteth chastely kisses his cheek. "Take your time."

"It's a lot…" Byleth mutters. 

"Shall I say it then?" The teasing lilt to Seteth's voice turns Byleth beat red. 

"No," Byleth turns away bashfully. "If you do I might combust." Nevermind that Seteth was just _inside_ of him. 

"Then what would you like me to do?" Seteth says gently. At first glance, Byleth comes off as prickly, maybe even cruel. He's difficult to understand even by the students that love him so much. One must be patient and Byleth will tell you exactly what he wants. 

"H...hold me. " Byleth replies carefully. "While we sleep. I want to stay. With you." Seteth smiles but there's one thing they have to do before they fall asleep. "No?" 

"Not yet, stay here and I'll clean us up first." Seteth gets up and finds the towel he'd set aside before Byleth came to his room. While he cleans up, Byleth asks,

"Does it always feel like that? Because I've never…" 

"It does. For our kind." Seteth says. Byleth still has trouble wrapping his head around his new lineage. He would have to find out about this sooner or later. "The stronger the emotional bond, the more intense it is." 

"Yeah…" Byleth mutters as Seteth cleans them both up. He has a lot to think about. Too much, honestly, and he's too tired to sort through everything swimming through his head. Despite what people say, Byleth has loved many times before. He loved his father and he loves Edelgard, Claude and Dimitri just as much. But Seteth is special. As the older man joins him in bed and wraps his arms around him, he melts into his warmth. 

"How do you feel now, my love?" Byleth's heart gives a little flutter and all his troubling thoughts are instantly put to rest. He smiles as he eases into sleep.

"Peaceful." 

**Author's Note:**

> I'm still working on the other fics, don't worry.


End file.
